Chainlink Data Feeds Skill

Chainlink Data Feeds Skill

Overview

Route Data Feed requests to the simplest valid path. Generate working code on first attempt when possible. Fetch documentation only when a specific gap blocks progress.

Progressive Disclosure

• Keep this file as the default guide.
• Read references/reading-price-feeds.md only when the user wants to read a price feed on EVM, write a consumer contract, read off-chain, look up AggregatorV3Interface, or debug a price feed integration.
• Read templates/starter-kit/README.md and the files in templates/starter-kit when the user asks for a working example project, Foundry starter kit, runnable Data Feeds example, or says something like "give me a working example of a data feeds project." Use this starter-kit template instead of inventing project scaffolding.
• Read references/mvr-feeds.md only when the user asks about Multiple-Variable Response feeds, bundle feeds, or BundleAggregatorProxy.
• Read references/svr-feeds.md only when the user asks about Smart Value Recapture, OEV recapture, or searcher onboarding.
• Read references/feed-types.md only when the user asks about feed categories, SmartData/RWA, rates/volatility, tokenized equity feeds, or needs help choosing a feed type.
• Read references/multi-chain.md only when the user targets Solana, StarkNet, Aptos, or Tron.
• Read references/feed-operations.md only when the user asks about L2 sequencer uptime checks, feed deprecation, contract registry, developer responsibilities, or data sources.
• Read references/official-sources.md only when the answer depends on live data that the reference files do not contain -- feed addresses for a specific chain, current deprecation schedules, specific network parameters.

10. Read references/source-code.md only when debugging interface mismatches or the user needs to inspect contract source code on GitHub.

11. Do not load reference files speculatively.

Routing

• Use reading-price-feeds.md as the default for any EVM price feed request — this covers the vast majority of Data Feeds use cases.
• Use templates/starter-kit for project-level example requests, especially Foundry starter requests. Return a concise file tree, the relevant template files, install/test commands, and the Sepolia ETH/USD feed configuration unless the user asks for another chain.
• Route to the chain-specific section of multi-chain.md for non-EVM chains (Solana, Aptos, StarkNet, Tron).
• Route to mvr-feeds.md for bundle or multi-variable feed requests.
• Route to svr-feeds.md for OEV or MEV recapture requests.
• Route to feed-operations.md for operational concerns (L2 sequencer checks, deprecation, monitoring).
• Ask one focused question if the chain, feed type, or integration method is unclear.
• Proceed without asking for read-only work: explanations, code generation, debugging.

Safety Defaults

These are non-negotiable in generated code. Every consumer contract or integration must include them.

• Always validate freshness: check updatedAt against a staleness threshold based on the feed's heartbeat. Never skip this.
• Always call decimals() on the feed: never hardcode decimal counts. Different feeds use different decimals.
• On L2 chains (Arbitrum, Optimism, Base, Scroll, etc.): always include an L2 Sequencer Uptime Feed check with a grace period after recovery.
• Never use answeredInRound for freshness validation — this field is deprecated.
• Remind users that example code is unaudited and not for production use without a security review.
• If the user is targeting mainnet, emphasize developer responsibilities and recommend a security audit.

Documentation Access

This skill references official Data Feeds documentation URLs throughout its reference files. Whether the model can fetch those URLs depends on the host agent's capabilities.

• If WebFetch, a browser tool, or an MCP server that can retrieve documentation is available, use it to fetch the referenced URL before answering.
• If no documentation-fetching tool is available, do not silently improvise Data Feeds patterns from training data alone. Instead:
• Use the embedded reference content in this skill's reference files as the floor for guidance.
• Tell the user that live documentation could not be verified.
• Provide the specific URL so the user can check it directly.
• For contract-first workflows where correctness matters most, prefer the concrete examples in references/reading-price-feeds.md over generating patterns from memory.

Working Rules

• Generate working code from knowledge and reference files first. Fetch only when a specific detail is missing.
• Treat 0-1 fetches as normal, 2-3 as the ceiling. Most questions need no fetches because the reference files contain the implementation guidance.
• When a fetch is needed, apply the cascade: WebFetch first; if it returns <1000 chars of useful content, fall back to curl -s -L -A "Mozilla/5.0 ..." "<url>"; if both fail, report the URL to the user.
• Keep answers proportional — a simple "read a price feed" question gets a code block and brief explanation, not a full tutorial.
• Generate code only when code is actually needed.
• Keep unsupported or out-of-scope features out of the answer rather than speculating.
• When using the starter-kit template, preserve its Foundry layout and contract names unless the user asks for a different framework. The template is based on the Chainlink Foundry Starter Kit PriceFeedConsumer.sol example, with the required Data Feeds validation added for safer generated code.